1. Field of the Invention
The present invention relates to a seat cushion structure, in particular to a seat cushion structure formed by combining upper and lower substrates made of a soft elastic material, and after the two substrates are attached with each other, a protrusion at the upper substrate is situated precisely above an upper periphery of an inwardly concave air chamber of a protrusion of the lower substrate, such that when a user sits on the seat cushion, a vast majority of the user's body weight is exerted onto the position of the user's buttock, and the design of producing different supporting forces is provided for supporting the user's body weight by the protrusions at different positions in the upper and lower substrates, and damping forces produced by the air chambers are provided for protecting buttock bones and an ergonomic form produced by different deformation forces of the air chambers can prevent the user's muscles from being ached or injured by excessive deformations, and the design of the air chambers and ventilation holes can dissipate the user's body heat through a flow passage along the periphery of the protrusions, while achieving the effects of pressure dispersion, ventilation, uniform support and protection.
2. Description of the Related Art
In general, a seat cushion structure emphasizes on its manufacture by a special advanced material with good ventilation and comfort. However, most seat cushions available in the market are made of foams with different levels of hardness. Although such arrangement can make some changes to the stylish appearance of the seat cushion, yet the density of the foams is equal and thus such seat cushion is unable to cope with a pressure change of the user's buttock when the user is sitting on the seat cushion. In other words, a vast majority of the user's body weight is exerted at the position of the user's buttock when the user is sitting on the seat cushion. Particularly, the largest force exerted on the buttock is concentrated at the position of the user's pelvic girdle, and a smaller force is exerted at the periphery of the buttock, so that the general seat cushion structure is insufficient to provide support for such pressure change, and the deformation of the buttock becomes larger. As a result, the seat cushion not only fails to eliminate a sitter's fatigue or relax the user's body, but also makes the sitter tired when sitting for a long time, and even worse, it may cause injuries to the buttock muscles or aches and pathological changes such as bone deformations, etc.